title: TLR4 and RAGE: similar routes leading to inflammation in type 2 diabetic patients.
abstract: OBJECTIVE
  The present study investigates the interaction of TLR4 and RAGE with their respective ligands as inducers of the inflammatory markers IL-6 and TNF-α. Also, the reactivity of peripheral blood mononuclear cells (PBMNC) from type 2 diabetic (T2D) patients and non-diabetic healthy controls (ND) were comparatively studied.
  
  
  METHODS
  Concentrations of IL-6 and TNF-α were measured by sandwich Elisa, using kits supplied by Assay Designs (Ann Arbor, MI, USA). PBMNC from T2D and ND were incubated in the presence or absence of LPS, anti-TLR4 or anti-RAGE for 72 hours at 37°C under 5% CO(2). The final volume was adjusted to 300 μL in DMEM supplemented with 10% fetal bovine serum. After incubation, the cells were centrifuged, the supernatant collected and the cytokines measured.
  
  
  RESULTS
  PBMNC from T2D were more sensitive to innate immune stimulation with LPS and monoclonal agonist anti-TLR4 than were cells from ND. The actions of LPS, anti-TLR4 and anti-RAGE potentiated the production of IL-6 and TNF-α in both groups. The simultaneous activation of monoclonal anti-RAGE and anti-TLR4 suggests that both antibodies used different receptors on the cell surface, but converged on the same PBMNC signaling metabolic pathways. This simultaneous activation induced a higher production of IL-6 and TNF-α in PBMNC from the T2D patients than from the ND subjects.
  
  
  CONCLUSIONS
  Our results clearly show an exacerbation of innate immunity in PBMNC with T2D that was possibly hyperglycaemia-induced. These data, when analyzed together, suggest the importance of innate immunity in the pathogenesis of T2D.
authors.affiliation: Hospital Santa Casa de Misericórdia de Belo Horizonte, avenue Francisco Sales 1111-9°D, Núcleo de Pós-Graduação e Pesquisa, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: C A
authors.initials: CA
authors.lastname: Veloso
authors.forename: J S
authors.initials: JS
authors.lastname: Fernandes
authors.forename: C M O
authors.initials: CM
authors.lastname: Volpe
authors.forename: F S
authors.initials: FS
authors.lastname: Fagundes-Netto
authors.forename: J S
authors.initials: JS
authors.lastname: Reis
authors.forename: M M
authors.initials: MM
authors.lastname: Chaves
authors.forename: J A
authors.initials: JA
authors.lastname: Nogueira-Machado
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000911:Antibodies, Monoclonal / Q000276:immunology / Q000494:pharmacology; D016022:Case-Control Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000378:metabolism*; D006801:Humans; D007249:Inflammation / Q000378:metabolism*; D015850:Interleukin-6 / Q000096:biosynthesis; D007963:Leukocytes, Mononuclear / Q000187:drug effects / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology; D008875:Middle Aged; D000067759:Receptor for Advanced Glycation End Products / Q000276:immunology / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects; D051197:Toll-Like Receptor 4 / Q000819:agonists / Q000037:antagonists & inhibitors / Q000276:immunology / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
chemical_list: D000911:Antibodies, Monoclonal; D015850:Interleukin-6; D008070:Lipopolysaccharides; D000067759:Receptor for Advanced Glycation End Products; C495345:TLR4 protein, human; D051197:Toll-Like Receptor 4; D014409:Tumor Necrosis Factor-alpha